1. Field of the Invention
The present invention relates generally to an image processing device, and more particularly, to an apparatus and method for composing images in the image processing device.
2. Description of the Related Art
Alpha blending is a technique of combining multiple source images by using weighted values of corresponding pixels in the source images to generate a composite blended image, wherein a foreground image has a translucency graphical effect. An alpha/transparency value for an alpha mask ranges from zero ‘0’ to one ‘1’, where 0 is a transparent pixel and 1 is an opaque pixel. The alpha value helps in blending foreground and background pixels, and the degree of contribution by the foreground and background pixels is determined from the alpha value.
However, the alpha blending does not use a correlation between the content information of images being blended, which often reduces visual appeal of the composite image by blending objects with the background/other images. The blending of the objects with the background/other images may partially or completely fade the objects, thereby compromising the visibility of the content of the object.
Image frequencies are subjected to interference effects in Alpha blending. Further, alpha blending introduces visual ambiguity by introducing fading in the composite blended image. Accordingly, it is often difficult to identify which feature belongs to which layer in an alpha blended image.
Further, in the alpha blending, alpha mask generation causes a visible seam and a ghosting effect. Specifically, visible seams appear when an overlap widow is too small or if the considered two images are very distinct. A ghosting effect occurs when a size of the overlap window is too large.
Present blending technologies depend on optimum window size to avoid a seam and/or a ghosting effect. Further, the present technologies do not address the problem of ghosting, when an overlap window size is fixed and cannot be changed during blending.